Interaction between opiate and 5-HT3 receptor antagonists in the regulation of alcohol intake.

Previous studies have shown that naltrexone and ondansetron, an opiate and 5-HT3 receptor antagonist respectively, can reduce alcohol self-administration. In the present study, we have shown a synergistic interaction between naltrexone and ondansetron in reducing alcohol intake in mice and rats. Small doses of ondansetron and naltrexone which are essentially ineffective on their own, produce powerful suppression of alcohol intake when given together. Although the exact mechanisms underlying this synergistic interaction remain to be explored, the combined use of these agents might have potential clinical importance.